Tikz：通过\ tikz {}绘制内部节点并连接没有间隙的线

Question

我正在尝试在节点内绘制并将线连接到其锚点。使用矩形可以很好地工作，但是当我尝试面对面连接两条线时，如下面的示例所示，仍然存在间隙。有人可以帮我告诉我如何消除差距吗？

围绕节点的[绘制]仅用于定向，我想保持边界不可见。

感谢您的事先帮助！

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}

% define macro for drawing inside node
\newcommand{\myMacro}[1]{
    \tikz[]{
            \draw[thick] ([xshift=0.2mm]2*#1,0) 
            -- (2*#1,0) 
            arc (0:180:2*#1)
            -- ([xshift=-0.2mm]-2*#1,0);
            \draw[thick] (0,0) circle (#1);
            \draw[thick] (0,-#1) -- (0,-2*#1);

    }
}

% node with drawing inside
\node[inner sep=0, minimum size=0, outer sep=0, draw=black!20, very thin](n1) at (0,0) {\myMacro{0.15}};

% connect lines to node.
    % blue circle: connection like it's supposed to be
    % red circle: connection with gap! :-(
\draw[thick] (n1.west) node[draw=red, circle, inner sep=0.05cm,  thin]{} -- ++(-0.5,0);
\draw[thick] (n1.east) -- ++(0.5,0);
\draw[thick] (n1.south) -- ++(0,-0.5);
\draw[thick] (n1.north) node[draw=blue, circle, inner sep=0.05cm,  thin]{} -- ++(0,0.5);

\end{tikzpicture}
\end{document}

Tikz Output

Answer 1

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}

% define macro for drawing inside node
\newcommand{\myMacro}[1]{
            \draw[thick] ([xshift=0.2mm]2*#1,0) 
            -- (2*#1,0) 
            arc (0:180:2*#1)
            -- ([xshift=-0.2mm]-2*#1,0);
            \draw[thick] (0,0) circle (#1);
            \draw[thick] (0,-#1) -- (0,-2*#1);
}

% node with drawing inside

\begin{scope}[local bounding box=n1]
\myMacro{0.15};
\end{scope}

% connect lines to node.
    % blue circle: connection like it's supposed to be
    % red circle: connection with gap! :-(
\draw[thick] (n1.west) node[draw=red, circle, inner sep=0.05cm,  thin]{} -- ++(-0.5,0);
\draw[thick] (n1.east) -- ++(0.5,0);
\draw[thick] (n1.south) -- ++(0,-0.5);
\draw[thick] (n1.north) node[draw=blue, circle, inner sep=0.05cm,  thin]{} -- ++(0,0.5);

\end{tikzpicture}
\end{document}